INFLUENCE OF THE GULF STREAM UPON CLIMATES. 49 



and that clothes the shores of Albion in evergreen robes ; while in 

 the same latitude, on this side, the coasts of Labrador are fast bound 

 in fetters of ice. In a valuable paper on currents,* Mr. Redfield 

 states, that in 1831 the harbor of St. John's, Nev^^foundland, was 

 closed with ice as late as the month of June ; yet who ever heard 

 of the port of Liverpool, on the other side, though 2^ further north, 

 being closed with ice, even in the dead of winter ? 



63. The Thermal Chart (Plate IV.) shows this. The isother- 

 mal lines of 60°, 50°, &c., starting o-ff from the parallel of 40° 

 near the coasts of the United States, run off in a northeastwardly 

 direction, showing the same oceanic temperature on the Euro- 

 pean side of the Atlantic in latitude 55° or 60°, that we have on 

 the western side in latitude 40°. Scott, in one of his beautiful 

 novels, tells us that the ponds in the Orkneys (latitude near 60°), 

 are not frozen in winter. The people there owe their soft climate 

 to this grand heating apparatus, for drift-wood from the West In- 

 dies is occasionally cast ashore there by the Gulf Stream. 



64. Nor do the beneficial influences of this stream upon climate 

 end here. The West Indian Archipelago is encompassed on one 

 side by its chain of islands, and on the other by the Cordilleras of 

 the Andes contracting with the Isthmus of Darien, and stretching 

 themselves out over the plains of Central America and Mexico. 

 Beginning on the summit of this range, we leave the regions of 

 perpetual snow, and descend first into the tierra templada, and 

 then into the tierra calientej or burning land. Descending still 

 lower, we reach both the level and the surface of the Mexican 

 seas, where, were it not for this beautiful and benign system of 

 aqueous circulation, the peculiar features of the surrounding coun- 

 try assure us we should have the hottest, if not the most pestilen- 

 tial climate in the world. As the waters in these two caldrons 

 become heated, they are borne off by the Gulf Stream, and are 

 replaced by cooler currents through the Caribbean Sea ; the sur- 

 face water, as it enters here, being 3° or 4°, and that in depth 40°t 

 cooler than when it escapes from the Gulf. Taking only this dif- 



* American Journal of Science, vol. xlv., p. 293. 



t Temperature of the Caribbean Sea (from the journals of Mr. Dun.sterville) : 

 Surface temperature, 83° September; 84° July ; 83°-86^° Mosquito Coast. 

 Temperature in depth, 48°, 240 fathoms ; 43°, 386 fathoms ; 42°, 450 fathoms ; 

 43°, 500 fathoms. 



D 



